Node-RSA 验证签名

/**
 * Created by Bluesky on 2015/9/8.
 */
var crypto = require('crypto');
/**
 * 验证签名
 * @param src_sign 签名源串
 * @param signature 已生成的签名
 * @param public_key 公钥
 * @returns {*}
 */
function verify(src_sign, signature, public_key) {
    // 构造PEM编码
    public_key = insert_str(public_key, '\n', 64);
    public_key = '-----BEGIN PUBLIC KEY-----\n' + public_key + '-----END PUBLIC KEY-----';

    var verifier = crypto.createVerify('RSA-SHA1');
    console.log('验证签名public key:\n' + public_key);
    console.log('验证签名src_sign:' + src_sign);
    verifier.update(new Buffer(src_sign, 'utf-8'));
    return verifier.verify(public_key, signature, 'base64');
}
/**
 * 在指定位置插入字符串
 * @param str
 * @param insert_str
 * @param sn
 * @returns {string}
 */
function insert_str(str, insert_str, sn) {
    var newstr = "";
    for (var i = 0; i < str.length; i += sn) {
        var tmp = str.substring(i, i + sn);
        newstr += tmp + insert_str;
    }
    return newstr;
}